High gain antenna
Everyone has seen many kinds of antennas, but why choose such antennas and why design them in this shape, do you know?
The rod/whip antenna is generally omnidirectional, i.e. it radiates uniformly at 360 degrees on the horizontal pattern, i.e. it has no directionality and generally has little gain. Such antenna applications are very common, and there are not many special requirements in use, such as Wi-Fi for household use, radio, station type of suburban county system in mobile communication system and so on.
Roof-suction antenna is a kind of antenna in mobile communication system. It is mainly used for indoor signal coverage, such as meeting room, hotel, office building, cinema, residential building, etc. Nowadays, indoor ceiling antenna in the market has many shapes and colors, but the purchase and manufacture of its inner core are almost the same.
Generally, there will be mobile or Unicom brand trademarks on the antenna, which can be seen at a glance which operator's signal is covered. The white downward projection is the antenna body, radiating the signal outward, and the cable connected behind is the feeder, which leads the signal from the mobile base station to the antenna.
Wall-mounted antenna
This wall-mounted antenna belongs to the air-dielectric microstrip antenna, which has strong directivity, large gain and beautiful appearance. It is used in some narrow indoor space. When the antenna is installed, there is no object in the near front area, and it is not easy to leak to the outdoor openings for windows, gates and other signals. Installed on the walls of rooms, halls, corridors and other places. The gain of the wall antenna is higher than that of the ceiling antenna, generally between 6 and 10 dB. High-speed non-stop toll collection system is also one of its major applications.
The Yagi antenna is a directional antenna with high gain. It was invented by Takeshi Yagi and Ota Takashi of Northeast University of Japan. It has the advantages of high gain, lightweight structure, convenient erection and low price. Therefore, it is especially suitable for point-to-point communication or introducing outdoor signals into the indoor environment. For example, it is the preferred type of outdoor receiving antenna for indoor distribution system. For example, indoor mobile phone signals in a certain area are particularly weak and hope to improve, the Yagi antenna is the first.
The more the number of elements of Yagi antenna, the higher its gain. Usually, Yagi antenna with 6-12 elements is used, and its gain can reach 10-15 dB.
Base station slab antenna is the most common and important base station antenna, which belongs to directional antenna. The advantages of this antenna are: high gain, good sector pattern, small back lobe, convenient control of vertical plane pattern, reliable sealing performance and long service life. The selection and setting of the antenna are relatively complex. According to the requirements of coverage, traffic distribution and anti-jamming, the parameters of dip angle, direction angle, antenna hanging height, antenna diversity distance and isolation distance should be strictly adjusted.
The gain of conventional base station plate antenna is about 14-17 dB. The gain of extended base station plate antenna can reach 16-19 dB. It is self-evident that the length of extended base station plate antenna is twice as long as that of conventional plate antenna, reaching about2.4 M.
Because the parabolic antenna has a good focusing effect, it has a strong ability to collect radiation. The gain of the parabolic antenna with a diameter of1.5 mcan reach 20 dB. Radar must concentrate its energy in the direction of illumination when launching, and only receive the echo in the direction of detection as far as possible while recognizing the azimuth and elevation of the target, so the antenna configuration is very common in radar or satellite systems. Some paraboloids adopt grid structure, one is to reduce the weight of antenna, the other is to reduce wind resistance.
SBX-1 Sea-based X-band Radar Antenna
Because of the curvature of the earth, the coverage of fixed radar is limited. The sea-based SBX-1 sea-based X-band radar consists of many small radomes and a phase array radar antenna weighing 1814 metric tons. The Phase Array Radar antenna requires more than one million watts of power to operate. It has more than 30,000 transmission and reception T/R modules, covering 384 square meters, and can search and track targets. It can also exchange information with the U.S. Missile Defense System at Vandenberg Air Force Base in California and the Rilleburg Base in Alaska, both of which have the
www.whwireless.com
